Photocopying



J. A. KOLIBAS A ril 29, 1969 PHOTOCOPYING I of 4 Sheet Filed May 20 1963 ATTORNE X April 29, 1969 J. A. KOLIBAS PHOTOCOPYI NG Sheet Filed May 20 1963 INVENTOR. Angs A.Ko1./aAs My 8% ATTORNE X J. A. KOLIBAS PHOTOCOPYING April 29, 1969 Sheet 5 of Filed May 20, 1963 INVENTOR. JAMEs A. KoL/ 5A5 BY W 0% @2- ATTORNEY.

April 29, 1969 Filed May 20, 1963 Llml J. A. KOLI BAS PHOTOGOPYING Sheet 4 of INVENTOR JAMES A Ken/5A5 BY QW- ATTORNE K United States Patent US. Cl. 355-40 8 Claims ABSTRACT OF THE DISCLOSURE A photocopier of the electrostatic type embodies means for accepting an original document fed in by the operator, feeding it downwardly past an exposure station and then returning the same to the operator. Switch means actuated by the original activates a charging station and triggers the feeding of a photoconductive copy sheet from a stack of sheets. The copy sheet moves horizontally through a charging station and an exposure station in time with the original, meanwhile controlling the energization of an illumination means by its leading edge and deenergization thereof by its trailing edge. The copy sheet then turns upwardly a short distance, and is finally returned in a generally horizontal path towards the operator via a liquid development bath and special offset-preventing squeegee rollers. A heater for drying the sheet is the final station before delivery. The feed path for the original includes a selectably settable guide such that the original can either be discharged or recirculated to produce plural copies. In the latter mode the illumination and charging apparatus are conditioned to remain continuously energized rather than being switched rapidly off and on.

This invention relates to photocopying, and more par ticularly to an apparatus and method for producing copy by the electrostatic process.

It is known to reproduce a document, or original, on a flexible copy sheet having an electrostatically charged photoconductive layer by first charging the copy sheet in an electrode assembly and thereafter exposing the electrostatically charged area to differential illumination as moderated by the original to thereby differentially discharge the photoconductive layer and produce a latent electrostatic image or pattern. Thereafter the latent image is developed and made visible by treatment with a powder containing pigment particles, or with a liquid containing pigment particles, which particles adhere to the surface of the sheet according to the charge pattern.

The copy sheet contains 011 at least one of its flat surfaces a photoconductive material such as zinc oxide dispersed in a resinous binder, as described by C. J. Young and H. G. Greig in the RCA Review for December 1954, pages 469' to 4 84.

It is with a method and device employing a copying principle of this nature that this invention is concerned, and a primary object of the invention is to provide a copying device in which the liquid developing technique is utilized.

Another object of the invention is the provision in a copying device for reproduction of a single copy, or multiple copies from the same original or document, as needed.

A further object of the invention provides for actuation of the various functions of the copying machine under initial control of an original document.

Another object of the invention is to utilize the copy sheet to control the actuation, as well as the arresting, of an illumination system.

Yet another object of the invention is the provision of means for maintaining the consistency of a liquid developer solution and for insuring a constant flow of the solution.

Still another object of the invention is to provide a document copying apparatus which is simple in construction, inexpensive to manufacture and convenient to operate and service.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings, in which:

FIG. 1 is a schematic illustration of the invention, showing the various stations in the copying apparatus, together with the document feeding and copy sheet feeding arrangements, and illustrating in broken lines, a portion of the equipment in an alternate position;

FIG. 2 is a fragmentary schematic view similar to a portion of FIG. 1, but illustrating the document feeding device when arranged for repetitive or multiple copy reproduction;

FIG. 3 is a schematic illustration of a means for feeding liquid developer to the developing station of the copying machine;

FIG. 4 is a detail plan, with parts broken away, of a blower device for the illumination system;

FIG. 5 is a schematic illumination of the drive mechanism of the apparatus of the invention;

FIG. 5a is a view taken on line Sal-5a of FIG. 5;

FIG. 6 is a schematic diagram of the electrical controls of the machine.

With reference to FIG. 1, 20 generally designates a feeding device having associated therewith a feed tray 22 adapted to receive an original document 24 which is to be copied. If but a single copy of the document 24 is desired, the travel of the document through the feeding device 20 is as indicated by the arrows, i.e., between the rollers 26 and 28, through a guideway G1, between rollers 30 and 32, between rollers 34 and 3 6, through a guideway G-2, and between rollers 38 and 40, and thence into an outlet tray 42. The rollers 26, 30, 34 and 38 are mounted on shafts 27, 31, and 39 respectively, and are driven rollers, whereas the rollers 28, '32, 36 and 40 are idle rollers.

As will be seen at the upper left-hand portion of FIG. 1, the entire document feeding device 20 may be swung upwardly, as shown by the dotted lines, so as to provide ready access to portions of an illumination system 1 and to original document 24 after the document has left the feed table 22. To this end, the operator merely raises clips against the force of spring 54, thus releasing the clips from the machine frame F. The feed table 56 is then slid to the left, as viewed in FIG. 1, disengaging pin 25 from slot 25a. The feed table is then removed from the machine, permitting access to the document feeding device 20. As stated previously, the document feed device 20 may then be swung upwardly about its pivot, shaft 31.

It will be noted that in the course of the travel of document 24, the document triggers a document switch S-6 and also passes in front of the illumination system I, the functions of which will be described in detail hereinafter.

As mentioned previously, one of the features of the copying machine of this invention is its versatility concerning the reproduction of a single copy or a multiple copies. Having described the path of travel of an original document for single copy reproduction, attention is directed to FIG. 2 for an explanation of the path of travel of an original document for multiple copy reproduction.

Thus, the original document 24, as in the case of single copy reproduction, is fed bet-ween rollers 26-28, through guideway G-l, between rollers 3042, between rollers 34-36, and thence through guideway 6-2. However, as

will be evident from the position of the arrows of FIG. 2, the document is then redirected between rollers 26-28 to commence another cycle, or as many cycles as required. The guideway G-2 is pivoted at 44 and may be positioned either downwardly as in FIG. 1, or upwardly as in FIG. 2, by any suitable manual control linkage.

The device or hopper for storing and feeding of photoconductive copy sheets which are to receive an image from an original document is designated generally as and comprises side guides '52, one at each side of the feeder, although for brevity of description only one such side guide is shown. A spring 54 is connected at one end to the frame of the copying machine and at its other end to a feed table 56 t0 thus retain the feed table in its uppermost position for a purpose which will become evident as the invention is described further. A weighted member 58 rests on the trailing edge of the topmost copy sheet 60 and assists not only in holding the copy sheets in alignment but also in acting as a retarding means for the pile of copy sheets as the topmost sheet 60 is fed from the pile.

Copy sheets 60 are fed from the pile by the starter roller or segment 62, mounted on shaft 63. The segment 62 preferably has a surface of rubber or the like, and is driven by a one-revolution clutch, as will be described hereinafter. By this means the copy sheet is caused to buckle against the roller 64, mounted on shaft 65. The roller 64 rotates in a direction opposite to that of segment 62. The copy sheet is thus forced to ride on top of the roller 64 and into the bight of driven roller 66, mounted on shaft 67, and idler roller 68 for processing at subsequent operating stations. A series of idler rollers 70 are mounted on the same shaft as segment 62 and serve to hold down and guide copy sheets 60.

As mentioned hereinabove, the copy sheet 60 is charged in an electrode assembly, which may take the form of corona generating device or the like, comprising an upper unit and a lower unit generally indicated at 72. Such a corona discharge device is well known in the art and is of the type which utilizes three approximately .002 inch diameter hard, stainless steel Wires.

Following the charging operation, the copy sheet 60 is exposed by an illumination source at an exposure station 74 as will be described more fully hereinafter.

The copy sheet is subjected to developing action in the developer supply tray 78 by a liquid developer solution, of the nature disclosed in Metcalfe et al. Patent No. 2,907,674, granted Oct. 6, 1959. The copy sheet 60 is then dried and ejected from the machine. In the course of travelling from the exposure station to completion, the copy sheet 60 is caused to pass between rollers 80 and 82, through guideway 84, between rollers 86 and 88, and through the developer solution in developer tray 78 by passing between plates 90 and 92. Plate 90 is a biasing plate which is grounded to the machine frame and serves to assist in the deposition onto the photoconductive surface of copy sheet 60 of the pigment particles carried by the developer solution. Copy sheet 60 then continues between a pair of squeegee rollers 94 and 96, and then rides over the top of heating element 93 and is ejected by rollers 100 and 102. Rollers 80, 88', -94 and 102 are mounted on shafts 81, 8 9, 95 and 101 respectively, and are driven rollers, whereas rollers 82, 86, 96 and 100 are idler rollers. It will be noted that squeegee roller 94, which is in contact with the image-bearing surface of the copy sheet, is preferably formed of chromed steel and is in contact with a pad 104, such as felt or the like. The pad removes excess moisture from the roller and thus assists in drying of the copy sheet 60 prior to contact of the copy sheet with heating element 98. It also cleans roller 94 of any excess pigment particles which it may pick up.

The heating element 98 is preferably of about 250 watts capacity and is effective to dry off excess liquid from the copy sheet 60 and to set, or harden, the developed image.

Any fumes from the liquid developer which may be present can be removed by a fan, not shown, placed adjacent the developer tray 78 and directed so as to exhaust away from the operators position.

As mentioned briefly hereinabove, the original document progresses through a path of travel which includes movement to and through an allumination system I. The functioning of a preferred form of an illumination system will now be described in detail.

After the document 24 passes between rollers 26 and 28, FIG. 1, through guideway G-1 and between rollers 30 and 32, it enters a scanning or viewing position, constituting a backing plate and an object glass 122, between which the document is fed. The backing plate 120 may be of any suitable material which will withstand heat, such as aluminum, for example, and is coated on the side adjacent the document 24 with a material such as white or light-colored silicone paint or the like which alfords a light reflective surface. Illumination is provided by an exposure lamp 124, excellent results having been obtained through the use of a 12-00-watt segmented quartz iodine lamp for this purpose. Reflectors 12-6 and 126a are employed so as to utilize the lamp 124 to its fullest extent by redirecting the light onto object glass 122.

Acting in conjunction with exposure lamp 124, see FIG. 4, is a cooling arrangement for the lamp which comprises a cooling device, indicated generally by the numeral 200, and includes for example a blower 204 of the ordinary centrifugal type. The blower is driven by shaft 205 which is actuated by a motor BM, not shown except in electrical diagram. The blower 204 serves to force heat generated by the lamp 124 through its housing 207 and through exhaust deflector 206 and thence out of opening 208 in a direction away from the operators station.

Referring again to FIG. 1, the image or pattern on document 24 which is to be reproduced is directed along light path 128, through a lens 130, onto a mirror 132, and thence through a narrow slit 75 at exposure station 74, at which point the image or pattern on document 24 is reproduced on the electrostatically charged photoconductive surface of copy sheet 60. The charge in the illuminated areas is thus dissipated and a latent electrostatic image is thereby formed on copy sheet 60 of the document to be reproduced.

It is particularly pointed out that the speed of travel of original document 24 and the speed of the copy sheet 60 are equal, thus providing a l-to-l reproduction of the pattern on the original document onto the copy sheet in a smooth, uncomplicated manner.

FIG. 3 discloses a means for supplying liquid developer solution to the developing tray 78 and will now be explained in detail.

Indicated generally at P is a pump arrangement which includes a container for developing material 152. Two rods 154, threaded at their upper ends, are anchored to the top of container 150 by nuts 156, and serve as a frame-work for pump shaft 158. Shaft 158 is driven by a motor PM and has aflixed at its lower end a paddle or fin-like member 160. As motor PM rotates shaft 158 and fin 160, liquid developer material is forced through outlet tube 162 and flexible hose 164. Hose 164- is connected to inlet 166 of the liquid developer tray 78.

In order to insure that there is an adequate supply of liquid developer in tray 78, an overflow tube 168 is provided which extends substantially above the bottom of tray 78. Connected to the overflow tube 168 is a flexible hose 170 which, in turn, is connected to inlet tube 172 to permit the return of excess quantities of developer material 152 to container 150' for recirculation through the pumping system. In addition to insuring an adequate supply of liquid, this arrangement also serves a purpose which is of considerable benefit; i.e., it permits a continuous flow of developer solution and thus provides a condition which might best be termed agitating the liquid developer to the end that the pigment particles are constantly kept in motion in the liquid carrier or vehicle, and a uniform dispersion assured.

In the course of producing copy sheets according to this invention, pigment particles contained in the liquid developer 152 are caused to adhere the latent electrostatic image by passage of the copy sheet 60 through tray 78. As explained previously, following passage through tray 78, the copy sheet 60 is fed between a pair of squeegee rollers 94-96 which remove excess developer material. Since only the pigment particles adhere to the image, the developer material which is repelled by the squeegeerollers is, for the most part, the vehicle or carrier portion of the liquid developer. Thus, there may occur a gradual weakening of the effect of the liquid developer to the extent that developed images on the copy sheets may become lighter and less pronounced. To compensate for any such weakening of the image, the invention provides for replenishing of the pigment particles through the addition of highly concentrated liquid developer to the normal supply of developer. A preferred embodiment. of a means for adding the concentrated developer will now be described.

With reference to FIG. 3 there is shown a reservoir 180 for containing concentrated liquid developer 182. Mounted within the reservoir is a barrel or cylinder 184 adapted to receive a slidable member or piston 186. A compression spring 188 is provided to normally maintain the piston in the position shown in FIG. 3. Connected to piston 186 is a plunger 190. As will be readily recognized, depression of the plunger 190 and piston 186 will force the concentrate through outlet 192, through flexible hose 194 and through inlet tube 196 into container 150.

The drive mechanism of the copying machine of this invention will now be described with reference to FIG. 5, as related to FIG. 1.

Each of the driven rollers previously described has associated therewith a sprocket mounted on the same shaft on which the roller is mounted. For purposes of clarity and orientation, the following tabulation is given so as to set forth the relation of each of the driven rollers to its shaft and to its sprocket.

Shaft Sprocket As will be evident from FIGS. 1 and 5, the feeding device for conveying the original document 24 is actuated by means of the rollers associated with sprockets 2.20, 222, 224 and 226, all of which are driven by the chain 250. Sprocket 252 acts as a takeup means, i.e., to take up any slack in chain 250.

In a like manner, feeding and controlling passage of the copy sheet 60 into and through the various stations of the copying machine is accomplished by means of the rollers associated with sprockets 222, 228, 230, 232, 234, 236, 238 and 240, all of which are driven by the chain 254. Sprocket 256 provides means for taking up any slack in the chain 254.

Main drive shaft 258-A is actuated by drive motor DM not shown except in the electrical diagram, and is effective to drive sprocket 258, and thereby chain 254, which in turn drives sprocket 222 and roller to afford feeding of the original document 24 and copy sheet 60 in timed relation with each other.

As mentioned previously copy sheets 60 are fed from the pile by segment 62 which is driven by a one-revolution clutch. A clutch of this nature is represented by the numeral 260, FIGS. 5 and 5a, and consists of member 262 which is engaged with shaft 264, and member 266 which is afiixed to stub shaft 268. A spring-urged pawl 270 normally engages a slot 272 in the clutch member 266. Pawl 270 is moved to the right, as viewed in FIG. 5, by a solenoid 304 as will be described hereinafter in connection with the operation of the machine. In the interest of brevity, it is deemed necessary at this time to merely mention the presence of the one-revolution clutch 260 and the fact that upon its actuation, shaft extension 268 and sprocket 264 will be turned one revolution in a counterclockwise direction acting on chain 276, thus rotating sprocket 230, shaft 65, and roller 64 in a clockwise direction. Simultaneously therewith, chain 276 acts to rotate sprocket 228, shaft 63, and segment 62 counterclockwise. Meanwhile sprocket 278 is rotating continuously under control of chain 254.

Referring to FIG. 6, a description will now be given of the electrical circuitry of the copying machine of this invention.

The mains L1 and L2 are completed or interrupted by cooperating starting switches S3, S3 and by safety switches S1 and S2 respectively. Across the mains are connected a machine pilot light MPL, by a conductor 301, a fan motor PM by a conductor 303, a pump motor PM by conductor 305, a blower motor BM by conductor 307, a drive motor DM by conductor 309, and a heat lamp 98 by conductor 311.

The solenoid of an exposure lamp relay R1 is connected between mains L1 and L2 by a conductor 313 which may be completed or interrupted by a copy sheet sensing switch S7 (FIG. 1). The latter detects and-is closed by a copy sheet 60 being fed towards the charging station 72. Tapping off of conductor 313 between relay R1 and switch S7 is a branch conductor 315 which contains normally open contacts Rla of relay R1 and normally open contacts R3d of another relay subsequently to be described. The solenoid of a locking relay R2 is connected between L1 and a contact A by conductor 317. A rectifier D1 is connected between L2 and a contact B by a conductor 319. Contacts A and B are adapted for alternate engagement with the blade of an exposure termination switch S4 which is held against contact B by the presence of a copy sheet and is normally free of both contacts. However, release of the feeler will allow the blade to touch contact A momentarily before opening. The blade of switch S4 is connected by a conductor 321 with a capacitor C1 which i connected with L1. Another capacitor C2, also connected with L1, is connected by a conductor 323 with conductor 319 at a point between the rectifier D1 and contact B. Conductor 323 includes normally closed contacts R3a of relay R3. A branching conductor 325, connected to conductor 323 between the contacts R3a and capacitor C2 leads L1 via normally open contacts R3b of relay R3 and the one-revolution clutch solenoid 304.

The main control circuit includes the solenoid of control relay R3 and document switch S6 which are in series connected between L1 and L2 by a conductor 327. A counter solenoid 306 is connected in parallel with the control relay R3 to be energized each time the relay is energized. An alternate path is provided around the document switch S6 and includes in series in a conductor 329 normally open contacts Rlb of relay R1, normally closed contacts R2a of relay R2 normally open contacts R3c of relay R3, and recycling switch S5. The latter is associated mechanically with the apparatus for adjusting guideway G-2 between single copy and recycling positions. When in the former, S5 will be closed on a contact E in conductor 329, and when in the latter on a contact F in the charging circuit to be described.

The charging circuit includes a conductor 331 which connects with conductor 315 at a point between contacts RM and Rla and proceeds via contact F and the primary of a transformer 302 to L2. The secondary of the transformer 302 feeds the corona discharge device 72.

The exposure lamp 124 is connected between L1 and L2 by a circuit which includes conductor 333 and an autotransformer 335 for adjusting illumination intensity. Also in series in this circuit are normally open contacts Rlc of relay R1.

Closing of the starting switches S3S3 on mains L1 and L2 is efiective to light the machine pilot (ready) light MPL, energize the fan motor PM, the pump motor PM, the blower motor BM, the drive motor DM, and the heat pump lamp 98. Cam-operated switches S1 and S2 are in series with starting switches 83-83 and may operate to deenergize the circuits for example, upon removal of the cover of the machine.

Closing of the copy sheet switch S7 energizes exposure lamp relay R1, which has three normally open contacts Rla, Rlb and R10. Contact Rla provides a circuit via conductors 313, 315 and 331 to energize the high voltage transformer 302 which feeds power to the corona discharge device 72. Contacts Rlb are part of the holding circuit for main control relay R3. Contacts R10 are effective to energize exposure lamp 124.

When the exposure termination switch S4 is in the A position, which it occupies only momentarily, relay R2 is pulsed by the discharge of capacitor C1 and momentarily opens contact R2a associated with the holding circuit for main control relay R3. Relay R3 has associated therewith one normally closed contact R341 and three normally open contacts R3b, R3c and R3d, and is energized by the closing of document switch S6. A holding circuit for the main control relay R3 is maintained through switch S5 and contacts R3c, Rlb and R2a. Contacts R3a open the charging circuit to capacitor C2 at the same time that contacts R3b close, permitting the closing of a circuit from capacitor C2 to clutch solenoid 304 to pulse the same. Contacts R3d complete, with contacts Rla, a holding circuit for relay R1 and thus a holding circuit for exposure lamp 124. They also provide the main circuit control for the corona discharge device 72.

In summary, following is a description of the operation of the machine.

A supply of copy sheets 60 is placed on the feed table 56 and the copying machine is turned on by closing switches S3S3, thus lighting the machine pilot light MPL, and starting fan motor FM, pump motor PM, blower motor BM and drive motor DM, and also lighting heat lamp 98. An original document is fed from feed tray 22, between rollers 26 and 28 and into guideway G-1. The leading edge of the document closes switch S-6, energizing relay R3, and through contact R3d supplies power to the high voltage corona charging unit. Simultaneously, contact R3b connects the solenoid 304 for the one-revolution clutch 260 with capacitor C-2 and the momentary discharge energizes clutch solenoid 304, thus causing rotation of the segment 62 and roller 64 in the direction indicated by the arrows, FIG. 1, and forcing the topmost copy sheet 60 into the nip of rollers 66 and 68.

As the copy sheet 60 passes between rollers 66 and 68, the leading edge of the sheet closes switch S7, energizing relay R1 and closing contact Rlc, closing the circuit to the exposure lamp 124, thus activating the illumination system I. The copy sheet then passes through the high voltage charging unit 72 and receives an electrostatic charge on its photoconductive surface.

As the lead edge of the copy sheet 60 emerges from charging station 72, it immediately enters exposure station 74. Simultaneously therewith, original document 24 enters the scanning position by passing between backing plate 120 and object glass 122, thus directly exposing on copy sheet 60, through illumination system I, all images or markings which are present on document 24, and creating a latent electrostatic pattern corresponding thereto on copy sheet 60.

When the lead edge of copy sheet 60 reaches the terminus of the exposure station 74, it trips switch S4, moving it to position B, FIG. 6, and allowing capacitor C1 to 8 charge through rectifier D1. It should be noted that continuing operation of exposure lamp 124 is insured even after the trailing edge of the copy sheet passes beyond switch S-7 due to the hold-in circuit completed through contacts R3d and Rla.

After complete exposure of the copy sheet 60, the trailing edge of the sheet moves away from the switch S-4 and the switch S-4 then moves momentarily to position A. Capacitor C1 is discharged through relay R2, momentarily opening contact R2a. Relay R3 hold-in circuit is broken, and contacts R3a reclose allowing capacitor C2 to charge, contacts R3b, R3c and R3d open, dropping out relay R1 and shutting off the exposure lamp 124 through contact Rlc and deenergizing the high voltage charging circuit.

In the position shown in FIG. 6, manually operated switch S5 is effective to perform single copy reproduction. Thus, guideway G-2 would be in the position shown in FIG. 1. For multiple copies, switch S-5 assumes the opposite position of FIG. 6, with its blade on contact F, locking in relay R1 and high voltage charging unit 72. In this instance,-the guideway G-2 would assume the posi tion shown in FIG. 2.

As explained-previously, after copy sheet 60 leaves exposure station 74, it is guided into and through a liquid developer solution in the developer tray 78, thence between squeegee rollers 94 and 96. Immediately thereafter, the copy sheet comes in contact with heating element 98 and is then .ejected by rollers 100 and 102. Meanwhile the original document 24 has been fed to the outlet tray 42 or is returned to guideway G-l depending upon the setting of guideway G-2.

While the form of the invention shown and described herein is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the form disclosed herein, for the invention is susceptible of embodiment in other forms and variations. It will be understood, therefore, that the invention is claimed in any of its forms or modifications falling within the spirit and scope of the language employed in the appended claims.

What is claimed is:

1. In an electrostatic copying machine, means for feeding an original document along a first predetermined path, means for feeding a photoconductive copy sheet along a second predetermined path, a supply hopper for said copy sheet, means adjacent said second path for imparting an electrostatic charge to the surface of a passing copy sheet, exposure means spanning said paths for scanningly illuminating an original document as it moves along said first path and simultaneously incrementally exposing a copy sheet as it moves along said second path, means in said second path for treating the copy sheet with a developer to develop a latent electrostatic image thereon, means including an intermittently operable starting roller for withdrawing copy sheets one at a time from said supply hopper and injecting them into said second path, sensing means actuable by the arrival of an original document at a predetermined location in the first path, and means responsive to the actuation of said sensing means for temporarily activating said starting roller to start a copy sheet from said hopper and introduce the same int-o said second path in such cooperative timed relation to the motion of said original in said first path that said copy sheet arrives at the proper location in the second path to receive the exposure of the same original by which its starting was activated.

2. In an electrostatic copying machine, means for feeding an original document along a first predetermined path, means for feeding a photoconductive copy sheet along a second predetermined path, means adjacent said second path for imparting an electrostatic charge to the surface of a passing copy sheet, exposure means spanning said paths for scanning illuminating said original document as it moves past an illumination point in said first path and simultaneously exposing said copy sheet as it moves past an exposure point immediately following said charge imparting means in said second path, means, including a first switch under control of a copy sheet and located immediately upstream of the charge imparting means, for activating said exposure means as the copy sheet approaches said exposure point, means, including a second switch also under control of a copy sheet and located immediately downstream of the exposure point, for deactivating said exposure means as the copy sheet departs from said exposure point, and means for treating the copy sheet with a developer to develop a latent electrostatic image thereon.

3. In an electrostatic copying machine having a frame and an illumination station thereon, means for feeding an original document along a first predetermined path past said illumination station, means for feeding a photoconductive copy sheet along a second predetermined path, said original document feeding means being pivotally mounted for upward retraction away from said illumination station to provide access to the same, a supply hopper for said copy sheet positioned above said document feeding means, means mounting said hopper on said frame for ready removal therefrom to permit upward swinging of said document feed path means about its pivot.

4. In an electrostatic copying machine, means for feeding an original document along a first predetermined path, means providing an illumination station adjacent said path, means for feeding a photoconductive copy sheet along a second predetermined path, a charging station adjacent said second path having means for imparting an electrostatic charge to the surface of a passing copy sheet, an exposure station adjacent said second path and positioned after said charging station, exposure means spanning said paths for scanningly illuminating an original document as it moves along said first path past said illumination station and simultaneously incrementally exposing a copy sheet as it moves along the second path past said exposure station, means in said second path for treating the copy sheet with a developer to develop a latent electrostatic image thereon, means responsive to the arrival of an original document at a predetermined point in said first path for initiating feeding of a copy sheet into said second path and for activating said charging means, means responsive to the arrival of the lead edge of a copy sheet at a first predetermined point in said second path as it approaches said exposure station for activating said exposure means, and means responsive to arrival of the trailing edge of a copy sheet at a second predetermined point in said second path as it departs from said exposure station for deactivating both said exposure means and said charging means.

5. In a copying machine, means for feeding an original document along a first predetermined path, means providing an illumination station adjacent said path, means for feeding a copy sheet along a second predetermined path, an exposure station adjacent said second path, exposure means scanning said paths for scanningly illuminating an original document as it moves along said first path past said illumination station and simultaneously incrementally exposing a copy sheet as it moves along the second path past said exposure station, means responsive to the arrival of the lead edge of an original document at a predetermined point in said first path for initiating feeding of a copy sheet into said second path, means responsive to the arrival of the lead edge of a copy sheet at a first predetermined point in said second path as it approaches said exposure station for activating said exposure means, and means responsive to arrival of the trailing edge of a copy sheet at a second predetermined point in said second path as it departs from said exposure station for deactivating said exposure means.

6. In a copying machine, means for feeding an original document from a starting position along a predetermined closed path, said path including a guideway movable into one selective position for ejecting a document from said path before its return to starting position to terminate the original document feed after a single cycle of machine operation, and into an alternate selective position for causing the document to return to starting position and to execute any desired number of cycles of the document feed; means for taking a photoconductive copy sheet from a supply thereof and feeding the same along a predetermined path, means under control of said original document as it moves past a predetermined point in its predetermined path for automatically initiating the feeding of a separate copy sheet on each cycle of the document when said guideway is in its alternate selective position; means providing a charging station and an exposure station in the predetermined copy sheet path, means normally operated only during transit of a copy sheet past said charging station for imparting an electrostatic charge to the surface of a passing copy sheet, means normally operated only during transit of a copy sheet past said exposure station for illuminating an original document, and circuit means associated with said guideway and settable to a condition for maintaining continuous energization of said illumination means and said charging means in response to positioning of said guideway in said alternate selective position for document recycling,

7. In a copying machine, means for feeding an original document from a starting position along a predetermined closed path, said path including a guideway movable into one selective position for ejecting a document from said path before its return to starting position to terminate the original document feed after a single cycle of machine operation, and into an alternate selective position for causing the document to return to starting position and to execute any desired number of cycles of the document feed; means for taking a copy sheet from a supply thereof and feeding the same along a predetermined path, and means under control of said original document as it moves past a predetermined point in its predetermined path for automatically initiating the feeding of a separate copy sheet on each cycle of the document when said guideway is in its alternate selective position; means providing an exposure station in the predetermined copy sheet path, means normally operated only during transit of a copy sheet past said exposure station for illuminating an original document, and circuit means associated with said guideway and settable to a condition for maintaining continuous energization of said illumination means in response to positioning of said guideway in said alternate selective position for document recycling.

8. An electrostatic copying machine comprising:

feed mechanism defining a first feed path for an original document having a departure portion progressing substantially horizontally away from the operator for a short distance, then a portion progressing vertically downward a short distance, and then a return portion progressing in a direction towards the operator;

means providing an illumination station adjacent said vertical portion;

a feed table for fiat cut sheets of electrostatic copy paper located slightly above the level of said departure portion;

means providing an exposure station located beyond the end of the departure portion of the first path remote from the operator;

feed mechanism defining a second feed path for a sheet of copy paper progressing first substantially horizontally away from the feed table and from the operator to and past the exposure station, then, immediately following said exposure station, upwardly a short distance, and then in a return direction towards the operator;

/ means adjacent said second feed path providing a 1 1 charging station between the feed table and the exposure station, and a liquid development station and a drying station in the return portion of the second feed path all located substantially between the operator and the portion of the exposure station most remote from the operator; and

exposure means embodying a light path with a single substantially right angle bend intermediate said illuminating station and said exposure station for exposing a copy sheet in said exposure station in said second feed path to the image displayed by a document at said illumination station in said first feed path.

References Cited Magnusson 95l.7 X Francis 95l.7 Vyoerberg 951.7 X Johnson.

Limberger 95l.7 Barber 95l.7 David et al. 271-4 Coronado et a1 271-4 Place 8824 Rose 8824 Oldenboom 95l.7 Pavelk 9589 Metcalfe et a1 95l.7 X Giaimo 95l.7 Limberger 9589 Magnusson 95l.7 Johnson.

US. Cl. X.-R. 

